Lead Acid Battery Bank and intermittent high discharge loads

[frankypc]

So i have a brand new battery bank composed of Crown CR-220 batteries, rated for 220ah at 20 hours. 4 x 6v batteries 24v

Sometimes during the day i use a microwave to re-heat food. I do it in 30 seconds increments or so as I'm not really cooking, The microwave is rated at 1200 watts so its pulling 50amps from my batteries max for those 30 seconds and eventually the solar panels catch up and might split the load or even take on more but in general its still a full 50amps being pulled for a couple of seconds from the batteries.

That being said usually if its during the day the solar panels catch up and get those batteries back to full.

So.... all this talk to ask. Is this behavior OK for the batteries or I'm diminishing their life expectancy?

 

[Trukinbear]

Cycling them shallow like that they'll probably last longer.

 

[snoobler]

If the microwave is rated at 1200W, it's pulling more like 1800W.

If the battery voltage drops to the re-bulk or "boost" level, it will trigger the SCC to re-enter bulk/absorption/float cycle.

If the SCC remains in float, you're not pulling enough of a load to trigger a re-bulk which means you're hardly using any capacity.

1800/24 = 75A

75A for 30s/3600s/hr = 0.625 Ah = 0.625/440Ah*100% = 0.14%

You're losing more than that due to the Peukert effect (anything over a 22A load will reduce capacity below rated), but it's so little, who cares.

From a longevity standpoint, it's hard to imagine you're impacting your battery life at all.

 

[Berseker]

The little i know is that c/10 is the maximun drain for lead acid battery, = 22amps for you 220ah batts. 22amps x 6v = 130w approximately, so this is the maximum load to be placed on 1 battery. 130w x 4 = 520w. this is the max load to be placed on the bank

however on my 220ah 48v setup made up of 12v 220ah flooded battery, i occasionally put a 2200w steam pressing iron for 5 to 10 mins, at dusk, and the bank lasted for.5yrs before crapping out. actually 3 batteries failed , and 1 is still kicking. my batteries are flooded tubulars with supposedly thicker plates, dont know if thats what made them cope with the abuse

 

[frankypc]

Hi Berseker

That is good to know. My big loads will be very intermittent and in short bursts so im hoping that i might get at least 2-3 years out of this flooded batteries as long as i care for them properly.

This is my first system so i see that plenty of people consider their first bank the "testing and learning" tool lol so they usually run them to the ground. Im hoping to take care of them while maximizing their usage jeje